Frein de w andre



Aug. 30, 1927.

A. DEWANDRE MOTOR BRAKE 1N VEN TOR. ki fizz awe;

Jan 12. 1924 Orizina} Fil 49a gc c A TTORNE Y.

Reissued Aug. 30,

- UNITED" STATES Re. 1 ,723- PATENT OFFICE,

ALBERT'DEWANDBE, or L nen, BELGIUM, ASSIGNOR 'ro sooin'rn anomn smwo- :rnnm DEWANDRE, or LIEGE, BELGIUM} moron BRAKE.

Original in). 1,589,166, dated May as, 1925, Serial No. 685,814, filed January 12, 1924. A n auonm' reissue filed May 17, 1927. Serial No. 192,125.

The present invention relates to an-im- 'DlOVGd suction brake for vehicles equlpped vith internal combustion engines. in which the braking action is-produced by the'partlal vacuum created-by ftli'e suction of the englne, The part-nil'vacuum ,act-s on-a plston' working-in a cylinder which can be placedin'"communication with either the atmosphere, or with the suction pipe of the 10 engine. The 'object of the invention is to provide a. brake of the character specified comprismg a minimum nl'iiiiber'of parts-whose opertior'i is certain; the arrangementbeing such as to reduce 'to a minimum the amount of air exhausted by the engine for the braking requirements. c

According to the invention, the valves for controlling the communication of the bfdke cylinder with the partial-vacuum and with the atmosphere, are regulated by a member whose position depends upon the distance" 7 between the two parts of a lost-motionconnection. located between the brake pedalor other brake-controlling element, and the rodding connected with the brakes.

This member operates the valves in such manner that the one which controls the communication of the cylinder with the atmos- 0 phere is closed before theone which controls communication with the suction pipe of the engine opens and vice versa.

The movements of the valvecontrolling member can be effected by means of a flexible shaft or cable of the Bowden type the wire-and sheath of which are connected 'atone -end to the member in question and to I a fixed part of the apparatus respectively, and at the other end to the two parts of the 40 above-mentioned lost-motion connection.

Two constructional forms of the invention areillnstrated by way of examples in .the accompanying drawings, in which: v Figure 1 illustrates diagrammatically one form of the improved motor brake.

Figure 2 illustrates diagrammatically a second fornnthereof. i

Figure 3 is a diagrammatic View showing the relative positions of the valves when the brakes are out, that is in no rmal position.

Figure 5 is a similar view showing the in the chambers 2 and 2, beyon 3 under the'partialvacuum generated in the relative positions of the valves when the 5 brakes are being applied.

1 indicatesv the manifold of an internal combustion engine (not shown) and 20, a pipe leadingfrom a carbureter. y

A pipel" leads from the manifold to a chambe r',.2 formed in a valve casing 2, one end of the chamber 2 being connected by a pipe 2 to a cylinder 3- in which operates a piston 4, the outer end of which is connected by a rod or cable 5 to a leverarm 6 com Q prised in the brake rodding.

. Apipe 7 openinginto the atmosphere through a chamber 2 of the valve casing- 12. branches olfi the pipe 2.

In the'illustnated constructional form the T ing two valves 8 and 9 arranged refipectively v pipes 2 r and 7, to providetor "placing the cyllnder engine suction pipe 1, by the-workingefthe engine of thevehicle, or 'in communication with the atmosphere.

If communication with the atmosphere be cut off by closing the valve 9, and ifthe "valve 8 be then opened, as shown in Figure 5, the partial vacuum producedb the suc-. tion of the engine in the pipe 1 wil be transmitted to the brake cylinder 3.

The partial vacuum will draw the iston 3 towards the end of the cylinder'in t e direction of the arrow X, carrying along with it the cab or rod 5 that is connected to the brake rodc ing in such a manner as to thereby produce the' braking operation. If at this moment the valve 8 be' returned to its closed position, as shown in Fig re 4, the piston 3. theoretically will remain in the position it is then occupying, until communication with the atmosphere has been reestablished, so as to allow the piston 4 to move back into its initial -position, o positely to the arrowX, by the action 0 return springs (not shown) providedat any point of the brake 'inst-allation.= v

For the purpose of co-oi'dinating the movemerits oi the piston in the brake cylinder with the degree of braking force desired b the operator, the distributorconsisting. oi the two valves 8, 9 is controlled from the brake pedal 13 by means of a fork 10 connected to the pedal; by a member 12 here shown as a Bowden shaft. The two prongs of the fork act directly-against stops 8 and 9, rovided on the ends of the tailpieces of t e valves 8, 9 respectively, for opening such valves, and'act oppositely on the valves through springs 11, to close the valves. That 15, spring 11 under pressure from the fork away from a particular stop will trans- 'mit the pressure to close the particular valve, while engagement of the: prongs with the, stops 8 or 9 will open the particular valve. The length of the tail pieces of these "valves is such asto ensure that the valves Considering first the position shown in Figures 1 and 3, it will be understood that the valve 9 must be completely closed before the valve 8 begins to open, .and vict versa, 6 c

It is also to be noted that the brake pedal 13'is connected to a lever arm 6', included -in the brake rodding, and-movable simultaneously and similarly with lever arm 6, by a coupling or lost-motion connection-14 comprising two elements 14 and 14* capable of sliding relatively to each other when pressure is applied to the pedal '13 in a direction indicated by the arrow Y.

In this arrangement, pressure exerted upon the pedal 13 against the tension of sprin 15, in the direction of the arrow Y, will rst relatively move the two movably related parts 14; and 14" of the lost-motion connection 14, whichis located between'the said pedal and the lever arm 6 of the brake roddmgl. The increase of this distance effects, t ro den shaft 12, a decrease in the distance between the fork 10 and the fixed point Z- on the ap aratus frame whereto is attached the.

end 0 the'flexible sheath member of said shaft. "Consequently, the fork is caused to swing in a clockwise; direction about its pivot, and as aresult of this movement the valve 9 tween the brake cylinder 3' and the atmosof theopened,

scribed, thesheath of'the Bowden. wire is tween the brake cylinder and the suction pipe 1 of the engine. In the operation deforced into curved form by the 'described movement of the pedal, causing the wire in ugh the' intermediary of the Bow:

which controls communication be-- movement of the wire exerts a pull upon the fork 10 in a clockwise direction to provide the action above described. A partial vacuum is thus set up in the cylinder 3 and the brake piston 4 moves in the direction of the arrow X, exerting on the rodding a force which tends to apply the brakes. As the brakes are applied, the lever arm 6 moves to operate the part 14* of the lost motion connection to follow the part 14? of such connection moved initially by the pedal, and if the movement of the pedal is interrupted,

that is stopped, the movement of the lost motion connection part 14 decreases the distancebetween the twoparts 14: and 14" of such connection, causing the fork to move in a counter-clockwise dlrection to an extent necessary to relieve the pull'on the stop 8 of valve 8 and exert pressure on the spring 11 of such valve 8, with the effect to close the valve 8. This movement under the described conditions will not, however, be suflicient to open valve 9 the valves being then in: the positions shown in Figure 4; Thus ,in this disposition of the parts the pedal is held in an operated position, both valves are closed and the brakes remain applied. If. an increased braking effect is desired, a further depression of the edal will have the effect described in the initial operation, that is will again increase the distance between the two moving parts 14* and 14 of the lost motion connection, move the fork clockwise,-

and open valve 8, opening the cylinder 3 to the suction of the engine and applying the brakes with additionalpressure, untilwhen the pedal is stopped, thelever arm, throu h its described movement of its part 14" of the lost motion connection will again. close valve 8 to hold the brakes set.

It will be apparent that, in consequence o the above described operation, each position of the pedal will correspond and determine a braking action of predetermined intensity;

that is the braking may be limited at any time by simply stopping the operative move- Y m'cnt of the pedal, and may be increased at any time and to any extent byra continuedand corresponding movement of the pedal.

With the brakes set, if the operator permits the pedal to return toward normal position through reduction of his pressure on the pedal and spring 15. the distancebetween the parts 14 and 14: of the lost motion connection is decreased. as the part 14 is held by the position of the brakes and the part- 14 moves toward part 14 by the pedal movement. The fork 10 moves counter clockwise and the valve 9 is opened, under the action of spring 21 to establishconimunication between the brake cylinder 3 and the atmosphere, pern'iitting the piston 4 to relieve the such sheath to move relatively toward the pull in the brakes. If the pedal is stopped during this return movement, the parts 14 and 14 of the 'lostmotion connection move relatively toward each other, the valve 9 closes, the relief movement of the piston 4 1s stopped and the brakes are thus held in what: ever set or applied position they may-then occupy. This permits the operator to relieve the braking force to any desired extent simply through appropriate movement of the If the pedal is permitted to move all the way back to its original or normal position, the releaseof the brakes will be complete, as the distance between the parts 14 and 14" of the lost-motion connection will be at its maximum, the fork will move counter clockwise to the extent to open valve 9, the atmosphere will be admitted to the brake cylinder. and the brakes will be relieved or thrown ofi by their springs and the piston 4 returned to normal position, the valves then being in normal position as shown In Flgure 3.

Moreover, it is to be noted that under any air leakage into cylinder 3 while the brakes are set. the braking action will tend to be reduced through rearward movement of the piston 4. In this actionthe lever arm of the rodding will move to increase the distance between the two parts 14 and 14 of the lost motion connection, and as aresult the fork will move in a clockwise direction, opening valve 8 and the engine suction will overcome the air leakage to maintain or restore the brakevaction. V

Assuming the motor means'inoperative, as when the engine is not running, an operative movement of the pedal 13 causes the lost motion parts 14" and 14 it) be moved rela tively to their limit. following which further pedal movement 'will directly apply the brakes, thus providing for a direct manual operation of the brakes.

In order to maintain a certain regularity of the partial vacuum in the cylinder 3, ,with the object ofpermitting the piston 4' to be actuated when the engine of the vehicle is stopped, I provide an intermediate reservoir 17 (Fig. 2) interposed between the suction ipe 1, and the pipe 2. leading to the cylinder '3. This intermediate reservoir is fitted according to this invention, with an automatic valve 19.

,VVhat I claim is:

1. In a brake system for motors, the combination, with a. suction pipe. and rodding for the brakes, of a brake cylinder-capable of being placed in communication with the, suction pipe or with the atmosphere. a piston working therein, and on which the en gine suction acts to effect the braking operation, valves for controlling the communicaw tion of the cylinder with said pipe and with the atmosphere, a brake. operating element, a lost-motion connectionbetween'said operat-ing elementand the brake-rodding embodying two movably-related parts and a movable element for directly actuating said valves operatively associated with said lostmotion connection so that its position depends upon the distance between the'movably-related parts of said lost-motion connection. v i 1 I 2. In a brake system for motors, the combination,with a suction pipe, and rodding for the brakes, of a brake cylinder capable of being placed in communication-with the suctionpipe or with the atmosphere, a piston working therein and on which the engine suction acts to efl'ect the braking operation, valves for controlling'the communication of the cylinder with said pipe and with theatmosphere, a brake-operating element, a lostmotlon connectionbetween said operating element and the brake-rodding embodying two movably related parts, and a movable element for actuating said valve operativcly associated with said lost-motion connection tl1ere-of;' said movable element closing the valve which controls communication between the brake cylinder and the atmosphere before it opens the valve controlling communication between said cylinder and the suction pipewhen such distance exceeds a given minimum extent.

3. In a brake system for motors, the combination, with a suction pipe, and rodding for the brakes, of a brake cylinder capable of being placed in communication with the suction pipe or with the atmosphere, a piston Working-therein and on which the engine suction acts to effect the braking operation, valves for controlling the communication of the cylinder with said pipe and with the atmosphere, a brake-operating element, a lost-motion connection between said oper ating element and the brake-rodding embodying two movably-related parts, a movable element for actuatingsaid valves and a flexible connection between the valve-actuating element and the lost-motion connection embodying a wire attached at one end toone of the parts of said lost-motion con nection and at the other end to said valveactuating element, and a sheath en'casing said wire and attached at one end to the other part of said lost-motion connection and at the other end to a fixed point on the v apparatus.

the brakes, "a," variable connection between and controlled by the relative positions of the manual element and the brakes, and

means controlled by the relative positions of such variable connection for directly actuating said valves to induce at will in the" power means such pressure dliferences as to:

set or maintain the braking action or nullify the power diiferences to release the brakes.

an element operatively connected with said valves and serving at relatively opposite limit movements to directly and reversely control the respective valves, a manuallyoperable element, a variable connection be- 'tween the manually-operable element and the braking mechanism, and means controlled by the relative positions of such variable connection to actuate the element for the corresponding control ofthe valves.

6. In a braking system for automobiles, a

'power means responsive to pressure ditfercnces, a connection between the power means and braking mechanism. a distributor for controlling the power differences and including a valve controlling the engine suction to the power means and a valve controllingan atmospheric vent to the power means, an element arranged between and independently movable relative to both valves, means whereby the element in its respectively opposite limit positions will directly open the respective valves, resilient means between such element and valve to cause the element when moving in a direction to open one of thevalves, to act through said resilient means to close the other of said valves, a -manually-operable element, a two-part connection between said element and the braking-mechanism, and

'means controlled by the relative positions of the two-part connection to operate the element for the control ofthe valves.

7. In a brake system for motors, a brake cylinder having a piston connected to the braking mechanism, valves for controlling communication of the cylinder with the suction of the engine or with the atmosphere, an operating element, means, and a lost-motion connection between the operating element and the braking mechanism serving in the relative positions of the parts of such connection to actuate sald valve operating means.

8. In a brake system mg mechanism, a cylinder havin for motors, braka piston connected to the braking mechanism, valves arranged in alignment and operating to control communication of the cylinder with the 'suction pipe of'the engine or 'withthe atmosv'a-lve operating the valves in apredetermine'd operation of said means.

9. In a brake system for motors, braking mechanism, a cylinder having a piston connected to the braking mechanism, valves controlling the admission of the engine suction and the atmosphere to the cylinder for controlling 'the' movement of the piston, a manually operable element, a two-part lost motion connection between the manual element and the braking mechanism, said parts being relatively movable through the movement of the manual element or through the movemcnt of the braking mechanism, and

means governed by the relative position'of said parts of the lost motion connection to control the operation of the valves, said means being responsive through the resultant movement of the parts of the lost motion connection-incident to a movement of the braking mechanism through leakage into the cylinder to open the valve controlling the engine suction to the cylinder to an extent and for a period to counteract such leakage.

10. In abrake system for motors, braking mechanism, a-cyli der having a piston connected to the brak ng mechanism, valves controlling and the atmosphere to the cylinder for con: trolling the movement of the piston, a manually operable element, a two-part lost motion connection between the manual element and the braking niechanisl'msaid parts being relatively movable through the movement of the manual element or through the movethe admission of the engine suction I too ment of the braking mechanism, and means governed by the relative position of said parts of the lost motion connection to con-' trol the operation of thevalves, said means being responsive through the resultant movement of the parts of the lost motion connection incident to a movement of the braking mechanism through leakage, into the cylinder to open the valve controlling the engine suction to the, cylinder to an extent and for a period to counteract such leakage, said lost-motion parts thereafter. acting through restoration of the brake action to closesuch suction valve. v

lntestimony whereof I afiix my signature.

ALBERT DEWANDRE. 

